In certain underground mining operations, conveyors are required that are not only capable of negotiating curves, but are also extremely long in design, for example, up to 200 meters in length, or longer. Such conveyors are required, for example, for chamber working in order to support a curve-negotiating conveyor belt that can follow a continuous mining machine even around curves. A special problem of extremely long conveyor systems is that the conveyor track, under the influence of the driving forces, can elastically expand by up to 1% of its length. Consequently, suitable measures must be provided to compensate for this extension of the track, especially when driving systems are used that operate in a positive manner.
It is therefore an object of the invention to create a curve-negotiating conveyor which can be designed with any desired length without causing problems due to elastic extensions of the conveyor track.
The invention provides a curve-negotiating conveyor system particularly useful for underground mining operations, wherein the conveyor track is forcibly guided in an undercarriage, and has its track links connected to each other with spatial flexibility, as well as with resistance to tension and compression. The undercarriage of the conveyor consists of undercarriage segments joined with each other with spatial flexibility. The segments are connected to each other with limited lengthwise displacement. Each individual segment has driving devices with sprocket wheels positively engaging the conveyor. With the conveyor of the invention, the track extensions which occur due to the forces of driving devices are compensated for by a corresponding lengthwise displacement of the undercarriage segments.
the displacements "s" of the individual undercarriage segments, the spacings "a" of the driving devices, and the pitch "t" of the elements engaging the conveyor track and the driving wheel are adapted to each other so that the sum of the displacement "s" of the undercarriage segments between two driving devices conforms to at least the pitch "t". In this way, each of the driving devices can be displaced relative to the tension and compression resistant conveyor track so as to provide a flawless engagement in the conveyor track.
According to a particularly preferred embodiment of the conveyor of the invention, the sprocket wheels of the driving devices simultaneously engage both the top and bottom strands of the conveyor track, so that the conveyor is maintained at a very low height profile.
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawing, which discloses a single embodiment of the invention. It is to be understood that the drawing is to be used for the purpose of illustration only, and not as a definition of the limits of the invention.